108 results about "Maximum power point tracking algorithm" patented technology

Distributed maximum power point tracking systems, structures, and processes are provided for power generation structures, such as for but not limited to a solar panel arrays. In an exemplary solar panel string structure, distributed maximum power point tracking (DMPPT) modules are provided, such as integrated into or retrofitted for each solar panel. The DMPPT modules provide panel level control for startup, operation, monitoring, and shutdown, and further provide flexible design and operation for strings of multiple panels. The strings are typically linked in parallel to a combiner box, and then toward and enhanced inverter module, which is typically connected to a power grid. Enhanced inverters are controllable either locally or remotely, wherein system status is readily determined, and operation of one or more sections of the system are readily controlled. The system provides increased operation time, and increased power production and efficiency, over a wide range of operating conditions.

Apparatuses and methods include a solar array having one or more string buses of series-connected solar modules. The current outputs from the solar modules on each string bus can be balanced along with the voltage output from the string buses. Local management units coupled between the solar modules and the string buses are configured to control the voltage output from each solar module. When the solar modules on each string are balanced, and when the string buses are balanced (or before the solar modules and string buses are balanced), an inverter or other device connected to the solar array can find the array's maximum power point via a maximum power point tracking algorithm.

The invention relates to a light-gathering wind and light complementary power station with an automatic sun tracking function and a maximum power point tracking function, which comprises a light-gathering device, a photovoltaic cell array device, a tracking driving device, a photovoltaic controller with a maximum power point tracking function, and a wind generating set, wherein the light-gathering device and the photovoltaic cell array device comprise a frame consisting of a Fresnel lens light-gathering device array and a photovoltaic cell array respectively; the tracking driving device comprises an intelligent control system for driving the light-gathering device and the photovoltaic cell array device to move in a sun-tracking manner, and a mechanical control and transmission device; the photovoltaic controller with the maximum power point tracking function consists of a voltage sampling circuit, a current sampling circuit and a microprocessor in which a multiplier and a comparator are arranged; and the wind generating set consists of a wind-driven generator and a wind turbine controller. The light-gathering wind and light complementary power station has high automation degree, light weight and high photoelectric conversion efficiency. By adopting the photovoltaic controller with the maximum power point tracking function, the investment cost of photoelectric power generation can be greatly lowered, and the power generating efficiency is greatly increased.

This invention relates to a method for Maximum Power Point Tracking (MPPT) a photovoltaic cell by a power converter that provides an output current at voltages useful to operate electronics or charge batteries. This invention also relates to a method for Maximum Power Point Tracking (MPPT) multiple photovoltaic cells by a power combiner that combines the output of the multiple photovoltaic cells into a single output. The power combiner is comprised of multiple power converters, one for each photovoltaic cell. Each power converter used in these methods has an input-regulating element that has an output wave form with a characteristic that is related to the photovoltaic cell voltage and current. As a result only the photovoltaic cell voltage is directly measured in these methods and the photovoltaic cell current is determined indirectly.

The invention discloses a control method for the maximum power point tracking (MPPT) of a photovoltaic power system. For the control method, on the basis of the traditional MPPT method, a judgement basis for the output characteristic change of the photovoltaic array is added, and a control strategy for the MPPT after the output characteristic change is improved. When the output characteristics of the photovoltaic array are remarkably changed due to a shadow or an assembly fault and the like, an operation point (U, I) on the I-U output characteristic curve of the photovoltaic array is rapidly adjusted to a straight line for connecting the origin of coordinates with a point (Uoc, Isc), and then tracking is performed to the maximum power point of the photovoltaic array starting from the operation point by using the traditional MPPT method. With the adoption of the control method for the MPPT of the photovoltaic power system disclosed by the invention, tracking can be rapidly and accurately performed to a global maximum power point on a multimodal output P-U characteristic curve of the photovoltaic array, and the fluctuation on the output power of the photovoltaic array due to the MPPT method during the tracking process is slight, so that the control method for the MPPT of the photovoltaic power system is good in application prospect.

A solar generator distributively performing maximum power point tracking (MPPT) has a plurality of solar cell modules formed by electrically connecting multiple solar cells, and a power conversion and transmission unit electrically connected with two power output terminals of the solar cell module. Each of the solar cells has a solar chip having two DC power output terminals and an MPPT unit having two power input terminals electrically connected with the two DC power output terminals, and two power output terminals. The solar generator performs MPPT associated with each solar cell, thereby ensuring the output power of the entire system a maximum power. When performing MPPT in a conventional inverter, maximum power of each solar cell is effectively acquired.

The invention discloses a maximum power point tracking method for a photovoltaic power generation system under non-uniform illumination. The method comprises the following steps of: detecting the output voltage U[k] and current I[k] of a photovoltaic array at the current moment, judging whether non-uniform illumination exists in the photovoltaic array through a maximum power point tracker, performing a variable step size perturbation and observation method to obtain the maximum power point if the illumination is uniform, and calculating the first reference voltage V0 if the illumination is non-uniform; obtaining the first local maximum power point by the variable step size perturbation and observation method, and recording corresponding voltage V1 and power P1; obtaining the second local maximum power point by the variable step size perturbation and observation method, and recording corresponding voltage V2 and power P2; by parity of reasoning, obtaining the voltage Vn and Vp, comparing n local maximum power points, extracting the maximum local maximum power point and taking the corresponding voltage as reference voltage Vnf+ output by the maximum power point tracker; and finally, calculating to obtain a duty ratio through a controller according to the Vnf+, and tracking the local maximum power point. The maximum power point tracking method has the advantages that the power loss brought by non-uniform illumination in the photovoltaic array in the system is reduced.

The invention discloses a photovoltaic power generation system virtual synchronous machine control method, control device, converter and system. The direct current side, connected with a photovoltaicmodule, of a photovoltaic inverter is connected to energy storage equipment and an energy storage converter; the voltage and current of the photovoltaic module are collected, a maximum power point tracking algorithm is carried out, a direct current voltage target value is obtained, and the energy storage converter is controlled to operate in a constant output direct current voltage mode accordingto the direct current voltage target value; direct current power output by the photovoltaic module is multiplied by the conversion efficiency of the photovoltaic inverter, the SOC optimal regulation power components of the energy storage equipment are superposed as an active power command of the photovoltaic inverter, and the photovoltaic inverter is controlled to operate in a virtual synchronousmachine mode according to the active power command. The application requirement can be met just by needing relatively small battery capacity, so that the maximum power generation capacity of a photovoltaic panel is guaranteed, the available rate and service life of the battery are optimized, and simultaneously, power support is provided for a power grid.

The invention discloses a method for controlling a three-phase current transformer in a photovoltaic grid-connected power generating system. The method comprises the following steps of: replacing the hardware phase locked loop algorithm with the software phase locked loop algorithm based on digital delay signal cancellation algorithm so as to quickly and accurately realize phase locking even in the unbalanced grid condition, and quickly and accurately searching the overall maximum power point in a photovoltaic array by using the overall maximum power point tracking algorithm to avoid unnecessary power disturbance and loss. The current transformer has good grid voltage abnormality ride-through capability by using the AC overcurrent and short circuit fault protection method based on three-loop control, the response speed and the reliability are high. For different impact loads or short circuit, the output current can be effectively limited. The adopted space vector pulse width modulation manner is applicable to a digital control system, and the duty ratio of the effective on-off vector of the three-phase current transformer can be calculated according to input signals so as to effectively control the on-off of the current transformer.

The invention belongs to the field of photovoltaic power generation, and discloses a MPPT control device of a photovoltaic generating system, which comprises an oscillating circuit, an MPPT circuit, a comparison circuit, a PWM generating circuit, a DC-DC circuit, a current detection circuit and a voltage feedback circuit, wherein the output ends of the oscillating circuit and the comparison circuit are connected with the PWM generating circuit; the output end of the PWM generating circuit is connected with the DC-DC circuit; the output end of the DC-DC circuit is connected with an accumulator, the current detection circuit and the voltage feedback circuit; the output ends of the current detection circuit and the voltage feedback circuit are connected with the comparison circuit; and the input ends of the MPPT circuit and the DC-DC circuit are connected with a photovoltaic array. A hardware circuit (MPPT circuit) is used for searching the maximum power point, and the duty ratio of the PWM is controlled to regulate the load impedance of the photovoltaic array, so that the photovoltaic array can work at the maximum power point, thereby enhancing the utilization ratio of the photovoltaic array. The invention has the advantages of easy realization, high efficiency, high stability and low cost.

The invention discloses a maximum power point tracking (MPPT) method of a currentless sensor, belonging to the technical field of new energy. In the method, because the ripple of voltages on a capacitor between a photovoltaic array and a convertor during the dynamic transition process comprises the information of the output power of the photovoltaic array, the variation direction of the output power of the photovoltaic array can be obtained by calculating the variation value of the voltages of the capacitor after two continuous MPPT periods so as to track the maximum power point of the photovoltaic array. Compared with the common MPPT method, the method provided by the invention has the advantages that the variation direction of the output power of the photovoltaic array can be judged without a current sensor, the maximum power point can be accurately tracked, the system cost is lowered, and the system reliability is improved, thereby having certain practical value. Thus, the method provided by the invention has wide application prospect in the aspect of new energy power generation, especially in solar power generation.

The invention discloses a power optimizer and a control method and a control device thereof. The method comprises the following steps: determining a current working mode of the power optimizer, wherein the power optimizer is provided with a plurality of working modes in advance, the plurality of working modes comprising a Boost mode, a Buck mode and a direct mode; if the power optimizer works in the Boost mode or the Buck mode currently, adjusting duty ratio of each switching tube in the power optimizer through a maximum power point tracking algorithm until meeting a first preset condition, and then, switching to the direct mode; and if the power optimizer works in the direct mode currently, switching to the Boost mode when meeting a second preset condition and switching to the Buck mode when meeting a third preset condition, thereby improving efficiency of the power optimizer.

The invention discloses a maximum power point tracking method based on disturbance observation. The method comprises the steps of firstly, sampling a photovoltaic array voltage, a grid voltage and a grid-connected current signal; then, establishing a dynamic model of a single-stage photovoltaic grid-connected generation system; finally, carrying out maximum power point tracking on the single-stage photovoltaic grid-connected generation system. According to the method, only the photovoltaic array voltage is detected, and a grid-connected reference current amplitude signal Iref is taken as an equivalent signal of output power of a grid-connected inverter, so that the influence on a maximum power point tracking algorithm caused by sampling quantization errors is lowered effectively, and the problems of the traditional disturbance observation methods that in the single-stage photovoltaic grid-connected generation system, the stability of the control strategy is poor and the bus voltage collapses or the output power oscillates are solved.

The invention discloses a coordinated control method for a photovoltaic virtual synchronous generator based on a common DC bus. The system studied in the method includes a photovoltaic assembly, a three-phase inverter, an energy storage battery and a bidirectional DC/DC converter, the maximum power point tracking algorithm is implemented through the bidirectional DC/DC converter, the inverter realizes the control for the virtual synchronous generator and the function decoupling of the photovoltaic assembly, the bidirectional DC/DC converter and the three-phase inverter, the energy storage battery carries out power balancing through the bidirectional DC/DC converter on the one hand so as to ensure the stable and reliable operation of the system, and stabilizes the DC-side bus voltage on the other hand. In addition, the maximum power output of the three-phase inverter in the invention lags behind that of the photovoltaic assembly through low-pass filtering with a large time constant, the requirements for coordinate control are reduced, and the influence of power fluctuation is reduced.

The invention discloses a photovoltaic power generation system environment self-adaptive type MPPT (maximum power point tracking) method. A voltage correcting parameter delta U and PI are introduced to control a link, a duty ratio D of a direct-current chopper is regulated in real time, maximum power point voltage Um optimal-searching speed is increased, the power loss is reduced, and the maximum power point voltage Um is changed in real time along with the environmental conditions, the incremental conductance method (I&S) optimal-searching step length is reduced, and the photovoltaic battery MPPT is quickly and accurately realized, the defects that a conventional MPPT algorithm is easy to affect by the environment, the robustness is poor and the power loss is relatively large are improved, and the defects that the intelligent type MPPT algorithm is complex and easy to be locally optimal are also avoided.

The invention discloses a maximum power point tracking control method for a photovoltaic inverter. The method includes the steps: S1, allowing the voltage of a solar panel to be periodically disturbed in a fixed direction at a large step V_step_big from an open-circuit voltage point oc to a short-circuit point o, and recording power Ppv and operating voltage Vpv in each disturbance; S2, when MPPT (maximum power point tracking) minimum voltage V_min is disturbed, finishing the fixed-direction disturbance, finding out the maximum value Ppv_max of all the recorded power Ppv during disturbance from the point oc to the point V_min and the corresponding voltage value Vpv_max; S3, periodically disturbing at a small step V_step_small with the Vpv_max serving as an initial point to perform maximum power point tracking; and S4, as for the single-way MPPT, judging whether the operating voltage of the solar panel is smaller than the operating voltage of a bus or not in a scanning or searching state. The maximum power point tracking control method integrates MPPT tracking speed and tracking precision, two-way MPPT can be performed at the same time, and the method is applicable to mounting conditions of various solar panels.

The invention provides a parallel inverter control method and system. The parallel inverter control method includes the steps that all slave machines receive all or part of variables and parameters of a maximum power point tracking algorithm, all or part of variables and parameters of a direct current voltage loop control algorithm and evenly-divided benchmark current signals, all or part of variables and parameters of a maximum power point tracking algorithm, all or part of variables and parameters of a direct current voltage loop control algorithm and evenly-divided benchmark current signals are sent by a host, and all the slave machines back up the variables and parameters of the maximum power point tracking algorithm and the variables and parameters of the direct current voltage loop control algorithm; When the slave machines judge that the host fails, one of the slave machines becomes a new host, the backup of the variables and parameters of the maximum power point tracking algorithm and the variables and parameters of the direct current voltage loop control algorithm are utilized for initializing the variables and parameters of maximum power point tracking and a direct current voltage loop, controlling and the even division of new benchmark current signals are carried out, and the evenly divided benchmark current signals are sent to the other slave machines. The parallel inverter control method has the advantages that the other slave machines can continue to work normally and power grid after the host fails, and no generated energy is wasted.

The invention discloses a maximum power point tracking (MPPT) method of self-adaption disturbance frequency and step, and particularly relates to a maximum power point tracking method of a solar photovoltaic cell and belongs to the technical field of new energy. The MPPT method comprises the following steps of: after each disturbance (namely changing an output voltage reference value of the photovoltaic cell), calculating the difference of the power before and after disturbance when the output voltage of the photovoltaic cell is in a steady state, and ensuring the judging accuracy of power changing direction; accumulating the power difference to accurately obtain the changing direction of the power after each disturbance; and regulating the disturbance step in real time according to the time of the reference values accumulated by the power difference, and regulating the reference values of the power accumulated values in real time according to the output power of the photovoltaic cell. Therefore, the maximum power point can be rapidly and accurately tracked, the disturbance frequency and the disturbance step near the maximum power point are minimum, the power loss caused by disturbance can be effectively avoided, and the maximization of the output power of the photovoltaic cell is realized.

The invention discloses a maximum power point tracking method for a photovoltaic power system. A maximum power point tracking algorithm is realized in a digital signal processor (DSP) by the current and voltage of a photovoltaic panel from a sampling unit and a current conditioning circuit to control pulse width modulation (PWM) output waveforms to realize power regulation. The maximum power point tracking of a photovoltaic array is realized by adopting a single-neuron adaptive proportion integration differentiation (PID) algorithm comprising the following steps of: initializing etaI, etaP, etaD, a and b, sampling the output voltage and current of the photovoltaic panel, calculating the derivative of power of a photovoltaic array over the voltage at a current moment, calculating an error and adaptively regulating a weight coefficient and a K value according to the magnitude of the error. Compared with the conventional maximum power point tracking algorithm, the invention improves maximum power point tracking accuracy and stability and increases maximum power point tracking speed.

The invention discloses a multi-peak photovoltaic array maximum power point tracking algorithm based on a jump strategy. When a photovoltaic array is evenly illuminated, a conductance increment method is adopted for maximum power tracking; when the photovoltaic array which is originally illuminated is partially shielded, maximum partial power points can be rapidly positioned through a constructed load line function on the basis of the conductance increment method, and therefore global maximum power point tracking is achieved. The tracking method is high in practicability, and is more obvious in superiority when the photovoltaic array is partially shielded. On the basis of the constructed load line function, the problem that traditional maximum power point tracking easily runs into local optimum is effectively solved, maximum power output is accurately achieved, and a new method is provided for multi-peak photovoltaic array maximum power point tracking.

A photovoltaic power generation system MPPT algorithm based on a voltage pre-estimating method is a maximum power point tracking algorithm applied to a photovoltaic array under complicate illumination conditions. The photovoltaic array is in a DMPPT circuit structure and a simplified equivalent output feature curve of individual photovoltaic cell mode in the photovoltaic array can be achieved; and a computational formula of work voltage pre-estimating value of the photovoltaic array formed by a serial connection of two photovoltaic cell sets under different light strength is achieved. In the photovoltaic power generation system MPPT algorithm based on the voltage pre-estimating method, the photovoltaic system is designed to be in a DMPPT circuit structure; a photovoltaic generation system output feature of the structure is employed to reckon the optimal voltage range of the work points of the photovoltaic array according to the feature curve principle; the optimized voltage pre-estimating value enables the system to effectively skip a secondary merit; after the optimal voltage range is determined, a P&O method is combined; and maximum power point tracking algorithm under complicate illumination conditions can be realized.